The invention relates generally to inductors. More specifically, the invention relates to a light-weight inductor used in power filters for multi-function motor controllers in aircraft engines.
When starting a traditional aircraft engine, the engine's shaft is rotated to operating speed by a pneumatic starter. Sparks are subsequently delivered to ignite a fuel/air mixture, which then powers the aircraft engine. This pneumatic starter, however, uses heavy components, which reduces the efficiency of the aircraft.
More recently-designed aircraft replace the pneumatic starter with an electric motor mounted on the shaft of the aircraft engine and a motor controller mounted inside the fuselage of the aircraft. Power is delivered to the electric motor from the motor controller by electric cables, and the electric motor rotates the aircraft engine's shaft up to operating speed. After the engine starting process is completed, the same motor controller is used to operate other motors, such as motors powering the Cabin Air Compressor (CAC) and the landing gear. This multi-function motor controller is called the “common motor starter controller” (CMSC). Included in the CMSC are three identical differential mode inductors. Up to 800 amperes (amps) at 0 hertz (Hz) is conducted through these inductors during the engine starting process, and up to 350 amps at 1450 Hz is conducted through these inductors during other motor applications.
Therefore, there is a need in the art for a differential mode inductor for use in a common motor starter controller that minimizes power loss and maximizes the extraction of heat generated by power loss, thereby keeping operating temperature below required limits. The inductor should also generate less heat than conventional inductors and be able to dissipate the heat that is generated over the high current range in which the inductor must function. Also, the inductor should be light in weight, since weight is often a significant factor in aerospace systems.